Personal watercraft (PWCs) are typically powered by a two or four stroke internal combustion engine that is connected via a driveshaft to a jet pump. While such engines provide ample power for PWCs, they create both noise and emissions that can be undesirable. For example, many bodies of water include designated “no wake zones” along shores, docks, and/or harbors in which watercraft must maintain a reduced speed. The goal of such zones is to, among other things, limit the amount of noise and emissions created in these zones. When PWCs are operated at low speeds in locations such as these, it is where preventing noise and environmental pollution is a high priority. Farther away from docks, people, and shore, riders tend to drive PWCs faster and increased power is highly desirable.
A desire has therefore developed for a watercraft that can alternately operate at low speeds while minimizing noise and environmental pollution and at higher speeds where increased power is desired.
In the field of land-driven wheeled vehicles such as automobiles, one way environmental and noise concerns have been addressed is to provide a hybrid vehicle that simultaneously and/or alternatively uses an engine and one or more electric motors to power the vehicle.
U.S. Pat. No. 6,857,918, issued Feb. 22, 2015, the entirety of which is incorporated herein by reference, describes various embodiments of hybrid propulsion systems for a watercraft. However, the arrangement of the engine and motor in the various embodiments can be bulky.
There is therefore a need for a hybrid propulsion system for a watercraft in which the engine and motor are in a compact arrangement.